Ruud FVIR (flammable vapor ignition resistant) gas water heater status light flashes indicating flammable vapor sensor (FVS) lockout; burner will not light.

Safety first: If you suspect a flammable liquid spill (gasoline, solvents), do not attempt to relight the heater. Ventilate the area and remove the source of vapors. Do not operate any electrical switches that could cause a spark.

• Step 1 – Eliminate vapors: Remove any flammable liquids from the area and ventilate thoroughly until all odors are gone.
• Step 2 – Inspect air intake: Check the combustion air openings at the bottom of the Ruud FVIR heater for dust, lint, or debris. Vacuum gently to restore airflow.
• Step 3 – Reset control (if allowed by manual): Some Ruud FVIR models allow a limited number of resets via the gas control valve procedure. Follow the lighting and reset instructions on the heater label exactly.
• Step 4 – Inspect/replace FVS: If the sensor has been contaminated or failed, it must be replaced with an OEM Ruud flammable vapor sensor. Turn gas OFF, disconnect the sensor wiring from the gas control, remove the sensor from its bracket, and install the new sensor.

If the unit remains in lockout after sensor replacement, the gas control valve/thermostat may need replacement by a qualified technician.